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By Kenta Suzuki, Toshiya Anami, Daisuke Shimosaka

"In an Al-Mn alloy heat exchanger fin stock, the effect of annealing conditions for as-cast and 0.1%Zr addition on recrystallization behavior is investigated using metallurgical analysis. Refinement of post-brazed recrystallized grains in fin stocks with Zr addition are suppressed for long-time annealing. In 0.1%Zr fin stocks, there was a decrease in the number of fine a-Al(Mn,Fe)Si dispersoids for pinning of sub grain and grain boundary. In addition, relatively homogeneous distribution of Al3Zr dispersoids was observed with increasing annealing time in as-cast. Homogeneous distribution of Al3Zr dispersoids can have a major effect on pinning of sub grain and grain boundary during brazing heat treatment. The homogenous distribution of fine dispersoids prior to brazing heat treatment is effective in causing the suppression of refinement of post-brazed recrystallized grain structure in aluminum alloy fin stocks.INTRODUCTIONAl-Mn based alloys are widely used as fin stocks in automotive heat exchangers because of their superior mechanical properties, braze ability, sagging and so on. In particular, coarsening of recrystallized grain structure is beneficial to avoid erosion, and achieve excellent sagging resistance (Lee, Yoon, Kim & Jung, 2002). For resisting grain coarsening, the alloys should contain a dense and homogeneous distribution of fine dispersoids to retarder crystallization (Humphyreys& Hatherly, 2004). It has been demonstrated that addition of Zr to Al-Mn alloys can shift recrystallization to higher temperatures because of the distribution of fine Al3Zr dispersoids in matrix(Pokoba, Cieslar& Lacaze,2012). According to Tohma, Asanoand Takeuchi (1987), coarsely recrystallized grain structure was obtained in 3003alloy with Zr addition after heat treatment. However, fine Al3Zr dispersoids are usually heterogeneously distributed because of segregation during casting and low diffusion rate of Zr in aluminum. Therefore, a homogeneous distribution of Al3Zr dispersoids can be achieved through long-time precipitation annealing(Jia, Hu, Forbord& Solberg, 2008)."

Jan 1, 2018

By G. F. Miller

ONLY IN THE Province of Saskatchewan is natural sodium sulphate found in Canada in amounts large enough to make recovery economically sound. Geologists have estimated that the numerous deposits within the Province contain upwards of 200 million tons of Glauber's salt. There are twenty-one deposits in the Province which contain 500,-000 or more tons and about two dozen with lesser amounts. The first recorded production of sodium sulphate in Saskatchewan was in 1918. The company concerned, and others that attempted to develop the industry in its early stages, were unsuccessful. Their failures were caused by two main factors -lack of knowledge of efficient operating methods and the unstable market situation for the finished product. Today, the situation is changed in both respects and the product, commonly referred to as 'saltcake", is a very important chemical requirement of many industries throughout the world. Before proceeding with remarks on manufacturing methods it should be stated that, although this is a general paper on the manufacturing methods and end uses of the saltcake produced in the Province, the writer is, of course, more familiar with the plants operated by Saskatchewan Minerals than with other operations and perhaps may be excused for dealing more particularly with the plants of that Compa11y.

Jan 1, 1958

By J P. Bolduc, P. E. Pelletier

Preceded by brief general considerations such as the development of the mining industry in. the Province of Quebec, the choice of plant location, the types of problems studied etc., the paper gives a complete description of this new research and treatment center for metallic, non-metallic and asbestos ores. Facilities for carrying out operations in the three sections of the plant -the sampling section, the ore treatment section and the asbestos section -are fully discussed as well as laboratory facilities for (a) the preliminary testing of ores prior to pilot plant treatment and (b) the grading and testing of asbestos fibre. AT THE beginning of the century, the annual value of the mineral production of the Province of Quebec stood at the $2,500,000 level. Twenty-five years later, it was just under $24,000,000. In 1950, half a century later, it was slightly in excess of $200,000,000. But in 1959, in the span of only nine years, it

Jan 1, 1962

By William M. (Bill) Shaver

"The author will review the early history of shaft sinking as well as focus on the improvements made in shaft design and construction over the last fifty years (1970 to 2019) to predict how shaft sinking will change over the next fifty years and describe what the shaft sinking world might look like in 2070. INTRODUCTION It is a great honour to be one of your keynote speakers for the Fourth International Conference on Shaft Design and Construction being held in Toronto in November 2019. This is one of the opportunities we have to thank the Mining Companies of the world as well as the industries and companies we serve for their support of the mining contracting and shaft sinking business of Canada and the world at large. Many of these companies are represented here today. Without your support many of the innovations we will talk about today would not be possible. We would also like to thank all the companies that work with us in our business including all the contractors and suppliers who provide the various services we require. These include equipment manufacturers, engineering companies, project management companies and suppliers large and small who cater to our every need as quickly as possible. Without all these partners we would not be as good as we are. Many of these companies are our sponsors this week. Thank you from all of us! This is also an appropriate time to pause and think about those Shaft Sinkers we have lost and those who have been injured on our projects around the world. Please bow your head and remember the Shaft Sinkers you have worked with, who did not return home or those who returned home injured. Think about how we can continue the work of making shafts safer every day as we go forward with our projects so everyone goes home to their families safe and sound. Pause for a minute and thank you. The subject matter we have chosen to discuss today is “Shaft Sinking in the Next Five Decades”. How will the work be done, how fast will it be done, what will it cost, and why we think this may occur? It is appropriate to consider this over the next few days with this auspicious group we have assembled. Today, we will look back at all the advances that have been made over the last many years and look ahead to the future to attempt to predict what shaft sinking will look like in 2070. When I look around the room I recognize that many of us will not be around then so we need not worry about being wrong. Suffice it to say that the next 50 years will be very interesting and exciting for the shaft sinking business."

Jan 1, 2019

By Hans Lundberg

During the last few years, geophysical methods have been introduced to aid mining geologists and mining engineers in locating mineral deposits. These methods have been developed as the result of investigations of various physical characters of minerals and rocks. In prospecting for ore-bodies, electrical methods have proved most successful. These methods are based on the great differences in electrical properties, and especially in conductivity, between ore minerals and rock minerals. The electrical resistance of the common minerals, rocks, and ores in ohms per cubic céntimeter is given in the following table: [ ] The first attempts at electrical prospecting were based on observing currents of polarization around certain ore bodies, which currents it was possible to measure. This method has been developed by Prof. Schlumberger and has been utilized by him successfully. He is represented on this continent by Mr. Sherwin Kelly, who has successfully operated the method here.

Jan 1, 1926

By . A. C. Atenas

Control of arsenic in the Potrerillos' Refinery electrolyte has been obtained by withdrawing a bleed stream of circulating electrolyte and ensuring the ratio of [O]/[As] in the cast anodes is maintained between 0.9 and 1.0. In order to achieve this control the anode oxygen must be adjusted, depending on the arsenic level in the cast anodes. It has been necessary to modify the time of the reduction step in the anode furnace refining process. Control of this ratio has permitted electro refining of anodes with high levels of arsenic, up to 3000 ppm, while minimizing the volume of electrolyte that must be removed for impurity control so as not to affect the copper concentration in the electrolyte. However this control strategy is not useful when the arsenic concentration in the cast anode is too high, because it is limited by the maximum oxygen concentration allowable for a good quality anodic. Costs have been reduced in anode furnace refining because it is no longer necessary to use alkaline flux injection to remove the arsenic in cast anodes.

Jan 1, 2007

By R. D. Brown

"""A matter of serious concern to the mining industry in British Columbia""; this comment reflects the attitude of the Mining Association of British Columbia toward the proposed new B.C. Mineral Royalties Act. The proposed legislation, introduced by the provincial government in February and now being debated by the legislature, combines a basic 5% royalty on the selling price, less approved p1ocessing and transpo1•tation costs, of minerals produced in B.C. with an ""excess"" royalty of 50% of any price increases over a predetetmined base. Government estimates project annual revenues of $20 million from the new royalty structure. The accuracy of these figures has been contested by the mining industry. Based on current world prices for copper the industry estimates that the provincial revenues from this mineral alone may run as high as $140 million in 1974 and $150 million in 1975. The Mining Association has warned that the new royalties “threaten to become confiscatory""."

Jan 1, 1974

By Neville Jordison

Indirect, gravity flow, heat exchangers have become a well established technology in mineral and metallurgical process plants. The technology is a conventional heat exchanger using high efficiency plates, with a free flowing bulk solid on one side of the exchanger and a fluid on the other side. This simple concept leads to many opportunities for achieving greater energy efficiencies in process plants. Indirect heat exchange is much more efficient than direct heat exchange using air such as in a fluid bed or rotary device. When air is used directly, large fans are required, it may also be necessary to chill the air, both high consumers of energy. By contrast, using water as the cooling medium requires only low horsepower pumps, typically only 10% of fan HP. Furthermore there are no stack emissions with the requirement for removal of dust or emissions. Indirect heat exchange also creates the opportunity to recover energy. This can work in two ways: energy can be recovered from a hot bulk solid, to heat pressurized hot water for steam generation or preheat air. Alternatively recovered energy from elsewhere in the plant in the form of hot water, steam, air or thermal oil can be used to preheat a bulk solid.

Jan 1, 2011

By Greg Yuriy

Over the past two decades, Vale Canada has used discrete-event simulation in a key role to support many underground mining studies. Traditionally, general purpose simulation software was developed for manufacturing and service applications. Not until recently have Mine Designers and Simulation Specialists been able to model the dynamics of underground mining scenarios without extensive manipulation of the inherent tools and entities contained within these simulation environments. This paper discusses Vale Canada?s past experiences with a variety of simulation software, describing model development methods and highlighting some of the lessons learned. The paper concludes with a review of recently considered software and provides a framework of desired attributes/functions for modeling mining scenarios.

Aug 1, 2013

By K. J. G Hedges

"Once a health based guidance limits for exposure to diesel exhaust have been established, and as part of a multi-disciplinary team, the program for exposure reduction should incorporate the plan-do-check-adjust cycle. Setting a suitably protective (health based) occupational exposure limit (OEL) for diesel particulate matter (DPM) and nitrogen dioxide is a key driver to reduce exposure. It is important to go beyond regulations and reduce exposure to diesel exhaust, DPM, as low as reasonably achievable (ALARA) such as that prescribed under the Australia, Queensland Mining and Quarrying Safety and Health Regulation 2017 where under section 135 Limiting workers exposure, the workers exposure must not exceed the exposure limit applying to the worker for the hazard; and is ALARA. It appears that previously acceptable OELs are no longer safe. Therefore it is important that the internal responsibility system be implemented and the precautionary principle approach be followed, especially as it may be some time before a suitably protective OEL specifically for DPM is in place. One leading multi-national mining company BHP Billiton has acknowledged a significant lag that exists between regulatory action and the level of science that informs health risk. This company is managing exposure to diesel exhaust to as low as technically feasible. This same company that has set an interim target for managing diesel exhaust to 0.03 mg/m3 is achieving these levels which paves the way for other mining companies and general industry including construction. The Occupational Cancer Research Centre 2017 recommends reducing personal exposure to within 0.02 mg/m3 (EC) for underground mining and 0.005 mg/m3 for other workplaces. Controlling DPM is important to prevent cancer however it is also important that that nitrogen dioxide (NO2) be reduced (ALARA) and that careful selection of control technology be considered such as the proper selection of a diesel oxidation catalyst so that the level of NO2 does not in fact increase. The example from BHP Billiton provides a leading practice including using a multi-disciplinary approach and the importance of controlling emission at source and having an auditable diesel emissions based monitoring program in place."

Jan 1, 2019

By K. G. Eriksson

"The first tentative test made to try rubber lining in grinding mills was made in the early twenties. However, because of poor rubber compounds and design the results did not prove to be promising.In the early sixties successful trials of rubber linings were carried out as a result of a cooperation between boliden AB and Skega AB.One of the reasons rubber was not used earlier for linings was the difference in wear characteristics between rubber and steel. The ability to successfully develop rubber mill liners depends on three factors:l. Design2. Material (rubber compounding)3. Experience (knowledge)DESIGNThe main difference between steel and rubber, in material aspect, is the elasticity and the low tensile and shearing strength of rubber. It is necessary to take maximum advantage of the elasticity and to reduce tensile and shearing forces by minimizing the sliding of the mill charge. This is accomplished by using the Lorrain type of liners, i.e., lifter bars and plates. It is, however, necessary to keep a certain balance between lifter bars to optimize liner life and grinding performance."

Jan 1, 1983

By G. G. Hatch

FOLLOWING World War II there was an urgent need for the development of domestic sources of ilmenite to take care of the expanding needs of the titanium dioxide pigment industry. In addition, there was the interest by the pigment manufucturers and others in titanium metal. Prior to the war the pigment industry in the United States had obtained its major tonnage of ilmenite, analyzing 55- ?60 per cent Ti02, from India. However, as a result of the shipping situation which developed during the war, the pigment manufacturers had to consider the use of lower grades of ilmenite located on this continent .and several companies undertook extensive exploration programmes to locate and develop such orebodies. Probably the most significant deposit that was found as a result of these ?programmes was the orebody .at Allard Lake, Quebec, owned by the Quebec Iron and Titanium Corporation. This ?Company was formed in 1948 by the Kennecott Copper Corporation and the New Jersey Zinc Company to mine this ilmenite ore and treat it in electric furnaces to produce titanium dioxide slag for the pigment industry and iron for the steel industry.

Jan 1, 1956

By R. A. Nemchek

ABSTRACT Concentrator plant design has evolved from large numbers of small grinding mills to small numbers of large mills. Consequently, plant performance often hinges on the productivity of a single large semi-autogenous grinding mill. Industry attempts to address the grinding mills’ critical nature frequently result in specifications that can be made simpler, more economical, and better focused on the project’s goals. This paper surveys current specification writing practices and proposes an improved approach recognizing that product design, procurement, manufacturing, and quality are interrelated in a successful project. The lessons learned here can apply to all types of machinery specifications.

Jan 1, 2014

By Harold J. Rose

"A VETERAN newspaperman once summed up a lifetime of observation and experience in these words:""What man can imagine, man can do"".That statement might well serve as the theme of a talk on research potentials of the coal industry or any other industry. It is not my intention today to make a series of predictions of things to come. Experience of the past few decades has shown that long-range predictions made be-fore engineering groups usually fall short of the mark; that is, the actual technical achievements in any period tend to surpass the boldest predictions that any responsible engineer would have made, say twenty years earlier.Instead, I will point out some recent accomplishments or refer to research that is in progress or now being planned in order to suggest important trends to be expected in the next few years. Based on this rapidly increasing tempo of achievements you can make your own extrapolations into the future."

Jan 1, 1959

By B. A. McKee, T. Adamcewicz

For a capital expenditure of only $46,000, Caland Ore Company has successfully converted its three dry grinding center peripheral discharge rod mills to dry grinding ball mills. The conversion has resulted in a significant capacity increase, operating cost reductions and in-plant environmental improvements. This paper describes why and how• the conversion was made.

Jan 1, 1972

By J. Spross

"The Key Lake mill has operated since the fall of 1983. The ore from both Key Lake open pits will be depleted by 1997. It is planned to use this mill, located about 60 km southwest of McArthur, to process the McArthur River ore.While the geological data collected so far on the McArthur deposit are encouraging, more information of the deposit is needed before any detailed mine planning can begin.The surface drilling program identified the orebody and provided information on the geomechanical and hydrological properties of the overlying sandstone. It was proposed to conduct an underground exploration program to further delineate the orebody. This was air proved following a public hearing and review process. This program involves the sinking of a 630 metre deep shaft and the driving of one or two drifts along a portion of the orebody. From these drifts, exploration drilling every 10 m to 15 m through the orebody will provide the information required for the preparation of a feasibility study and an Environmental Impact Statement (EIS)."

Jan 1, 1994

By S. E. Wolfe

AKNOWLEDGE of the density of a pulp or suspension is frequently required by the millman, to whom fluctuations in density, which occur in all mill circuits, are of importance and interest. There ,are many w.ays currently in use to determine density and probably the most common method is to take samples of the pulp. The proper sampling of the material is no easy matter, particularly when the pulp contains a sand fraction which settles rapidly. For example, when filling a liter container from the overflow of a classifier, it is al-most impossible to fill the can completely and yet prevent overflow. If there is an overflow, the pulp remaining in the can invariably has an excess of sand and the indicated density will be too high. To surmount such difficulties, and to obtain a continuous indication of the density of a pulp at any desired depth, the simple indicator shown diagrammatically in Figure l was designed by the writer in 1951. Its component parts, numbered as in Figure 1, are as follows.

Jan 1, 1958

By E. Godfrey

The average man one meets on the street thinks of an explosive as a medium of death and destruction, something unstable which should be given a wide berth, because he knows little or nothing about its use or its stability. Briefly, explosives are compounds that develop very large quantities of heat and gas in an extremely short time and in a small space, thereby exerting enormous pressure upon surrounding bodies, and by the rapid expansion of this highly heated gas are able to perform a considerable amount of useful work. The amount of heat generated and the volume of gas produced by the decomposition of an explosive determines the amount of mechanical work it can do, and the time occupied by its change from solid or liquid condition to gaseous condition determines its shattering effect. Explosives manufactured by reputable people are not extremely dangerous, on the other hand they are quite safe if handled in a proper manner. Furthermore, before an explosive can be placed on the Canadian market a sample must be submitted to the Explosives Division of the Mines Department, who may condemn or permit its manufacture, according to their findings regarding its safety in handling and its stability during storage.

Jan 1, 1926

By A. Robles-Vega

Personnel of Mexicana de Cobre, a subsidiary of Southern Copper located in Nacozari, Sonora Mexico have been working in the past few years on the development of a process to treat and manage, in an environmentally accepted practice, the residues and effluents generated during the process. To date, this team has been reviewing existing technologies and also has explored new alternatives. At the end of this phase, a novel, efficient and complete process has been configured which will be able to treat some solid and liquid streams such as Teniente converter dust, Peirce Smith converter dust, a Sb-rich precious metals slag, copper refinery electrolyte bleed, acid plant blowdown and an acid bleed of the precious metals plant. The process will consist of a leaching stage, followed by a very selective copper precipitation using novel technology which has been named as back reactions. After copper precipitation, impurities (As, Sb and Bi) will be precipitated mainly as arsenic trisulfide (As2S3) using H2S(g) which will be generated by means of a new process developed in our company. At the end of the process, small volumes of arsenic trisulfide will be vitrified and then disposed as a stable residue.

Jan 1, 2007

By W. J. Blackstock

Introduction To The great majority of people, the term 'strip coal' has little or no meaning, or if it has any significance it is thought to refer to a poor grade of coal that had to be accepted during the war because no other fuel was available. Few people in the Province of Alberta realize the magnitude of our coal stripping industry, and fewer realize that strip coal has been available to domestic consumers for at least forty years. Among the first in the field of strip coal mining in Alberta were the Tofield Coal Company, Ltd., and Sterling Collieries Company Ltd. It was not until the advent of World War II, with its huge drain on industrial and domestic coal sup? plies produced by the underground mines, that some other source of coal was seriously sought. The tremendous shortage of manpower du ring this period of National emergency made it imperative that any increase in the coal production must be procured on a high tonnage per man-hour basis. It was therefore natural that the highly mechanized strip mine should be eagerly encouraged and subsidized by the Governmental agency - the Emergency Coal Production Board - under the very able direction of Mr. G. A. Vissac.

Jan 1, 1949